1. Field of the Invention
The present invention relates to plasma processing of a substrate. More particularly, the present invention relates to a reactor apparatus for providing a high density plasma source for sputtering metal and dielectric films onto a substrate.
2. Description of the Prior Art
Magnetron sputtering is a known method of physical vapor deposition (PVD) for forming thin films on substrates of a variety of types. Magnetron sputtering is generally accomplished by creating a plasma within a vacuum chamber adjacent to the surface of a sputter target. The plasma is formed in a support gas introduced into the chamber at a very low pressure. A reactive gas may also be introduced into the chamber. An electrical potential is created within the vacuum chamber between the sputter target that is usually cathodic and an anode. The electric field generated by the potential causes the support gas to be ionized, thereby forming the plasma. A magnetic field is also provided to confine the plasma discharge. The magnetic field traps electrons so as to increase the number of collisions between the electrons and the support gas atoms. This, in turn, increases the ion population and intensifies the plasma.
Magnetron sputtering has become widely used in the semiconductor industry to deposit metallization layers in semiconductor devices. Because the dimensions of semiconductor devices have been reduced substantially over the years and the size of semiconductor wafers used to make such semiconductor devices has increased during the same period, the demands for precision sputtering have increased. Precision sputtering requires the generation and control of a high density plasma.